Portable potential-indicator.



PATENTED mm: 5, 1906.

J. B. TAYLOR. PORTABLE POTENTIAL INDICATOR.

APPLICATION FILED JUNE 10,1905. I

Inventor: John 3.1199101,

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Witnesses:

table oii-havmg UNlTEl) srrirns JOHN B. TAYLOR, OF SOHENECTA PORTABLE.FOTE DY, NEW v YORK, ASSIGNOR ELECTRIC COMPANY, A CORPORATION OF NEWNTRALQNDECIQTQFL Specification of Letters Patent.

Patented June 5, 1908.

Application filed June 10, 1905. Serial No. 264.606.

Z?) all whom it mrty mum/ 771,.-

fBe it known that I J on). B. TAYLOR, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York-haveinvented certain new and useful Improvements in PortablePotentialliidicaters, of which the following is a specification.

This invention relates to electrical instruments; and it consists in adevice for indicating whether or not an electrical conductor isalivethat is, whether its potential differs in greater or less degreefrom that of the earth or of the person using the device.

The invention comprises a glass tube tilled with a finely-dividedconducting substance held in suspension in a liquid insulator. Ametallic electrode is sealed into one end of the tube, and it the tubeis held in the hand and brought into proximity to acharged conductor thesuspended conducting particles become electrified inductively and areattracted to the electrode and to the walls of the tube. This motion ofthe particles causes a change in the appearance of the liquid and thepowder, which indicates that the conductor is charged.

In the accompanying drawings, Figure my invention. Fig. 21s a sideelevation of a modification thereof. Fig. 3 is a longitudinal section ofa further modification. Figs. 4 and 5 are cross sections of .F J. 3 onthe line 4C 4, showing the position of the divided me- K tailicsubstance when uncharged and when charged.

Referring first to Fig. 1, there is seen a handle 1, of hard rubber orother good insui lating material, in which is inserted a rod 2,01 metal,havinga tubular eirtension or sleeve 3, whir l1 projects beyond the endof the handle. Closely fitted into this sleeve is a glass tube 4,hermetically closed at each end and containing an inner concentric andsmaller tube 5. An elect-rode 6 of some suitable metal, such as.la-tinum, is inserted into the inner tube and extends beyond the endthereof at 7. It may be of any desired shape, and the greater itssurface the more quickly el'i'ects the movement ol the conductingparticles. The annular space around the inner tube is filler vwith alitpiid insulator 8-such gasolene,

benzene, reroscne, turpentine, or some vegein suspension ill it some 1is a. longitudinal section of a device embodying J end of the tubepowdered metallic substance, such as sulfid of tin or aluminium powder.There is also placed in the tube a small, quantity of mercury 9, bywhich the inner walls of the tube may be scoured upon giving the devicea rapid agitation.

Fig. 2 shows the device mounted similar to a fountain-pen. The tubularbarrel 10 partially incloses the sleeve 3 and the glass tube 4, thelower end of the latter being reduced in diameter and closed with astopper 11 before being hermetically sealed. T he electrode is in theform of-a strip 12, and

in a case it is in contact with the liquid instead of being inclosed inan inner tube. While being i carried in the pocket and out of use theexposed portions of the sleeve, tube, and electrode may be covered by acap 13.

In Fig. 3 the glass tube is inclosed in a sheath 14,0f hard rubber orother insulating material, a portion of which is cut away on one side soas to expose the glass tube. This form of the device protects thetube'from mechanical injury. The electrode 15 'is immersed directly inthe liquid and makes contact with an adjustable ti 16, projecting beyondthe end of the sheatii.

in case gasolene or other volatile and readily-ignited liquid is usedsome difliculty is ex perienced and some slrill'is required to seal oilthe tube after it has been filled. InFig. 3 the tube is shown ascontracted at the (point 17, and after the proper amount of liqui andpowder and mercury have been placed in the tube a. small cork 18 isforced into the contracted portion, making a tight joint. The can thenbe safely sealed off, as there is sufficient distance between said endand the cork to prevent the heat of the sealing-flamefrom evaporatingand igniting the volatile liquid.

The 0 ,eration of the device is as follows: It is helddn the hand of theo erator, and the projecting end of the electro e is approached to aconductor. In the case of high voltages it is not necessarv to makeactual contact with the conductor. If the latter is charged, thefloating particles in the liquid become I electrified inductively andare attracted to l the inside of the lass tube-and to the elecl trode orthe outside of the inner glass tube l when one is used. in the formshown in Fig. l l the device is virtually several condensers l inseries, the sleeve tending by electrostatic currents from that whichtakes place with 'eral the lighter liquids, such as gasolerc,

capacity to come to the same potential as the hand of the operator,while the outer surface of the inner glass tube inductively tends toapproach the potential of the electrode-that is, of the conductor undertest.

The motion of the conducting particles causes a change in the appearanceof the liquid and owder, which is the indication that the cond uctor ischarged. if sulfid of tin is used, the contents of the tube change fromagold color to a dark broi n. In some forms, depending on the size,relative position of electrodes, &c., the liquid changes color atmoderate voltages, while at hi her voltages the particles are attractedso 0 oscly to the walls of the glass tube that they form a coat ingwhich clings to the tube until removed by shaking, in which operationthe rnercurv assists very materially in mixing the liquio and the owder.This kind of indication while quite different from the change of coloris readily distinguished and in a rough way gives an opportunity fordifferentiating high voltages from. low ones.

The action somewhat different on direct alternating currents. Withdirect current there is a tendency for all of the metallic particles andthe inner surface of the glass tube to come to the same potential,because tli transfer of charges from the electrode tr the walls of thetube by means of the inovir irticles. As soon as this condition of epotential exists there is no attraction of 1 particles for each other orfor the tote ii the electrode, and indication ceases. in genreach thiscondition more rapidly than the heavier liquids. I may therefore useturpentine mixed with caster-oil or any other oil which will increasethe viscosity of the liquid, and thus retard the motion of the metallicparticles. llith clone the indications on direct current may appear anddisappear inside of one second, while with heavier liquids this time maybe increased to a number of seconds.

In the case of alternating currents the conditions are different, sincethe tendency is fonthe particles to go first to one elec/rodo and thento the cum-1 The indications niav be made more pronounced by placingsome coloring-matter in the liquid 7 e, black which as, for 1 makes agreater cont )1 the a lid of tin t so of aluinnninnrp v v n d contrastwitn g1 ..y color or i be seen that the device easily tran orted and hatthe being" sun inc-weed are not hitelv to be broken even witlroughhandling. As the active elements are hermetically sealed in glass,atmospheric conditions have no effect on the indications. The deviceconsumes an intinitesimal amount of energy, and its application toaconijluctor has therefore absolutely no effect on the system. Safety tothe user is insured by making the thickness of the glass andinsulating-handle suflicient to stand a potential many thousand voltsgreater than that of any circuit on which there is a chance of its beingused. The device has no delicate parts and requires no adjustment, sothat it can be used indiscriminately on circuits having either high orlow voltages without being damaged. it is applicable to bothdirectcurrent and alternating-current systems of any volt-a e and can beused in any position.

I do not desire to restrict myself to the particular form or arrangementof parts herein shown and described, since it is apparentthat they maybe changed and niodifiedwithout departing from my iiwention.

What I claim new, and desire to secure by Letters Patent of the UnitedStates, is

l. A potential-int icator comprising a vessel, movable particles ofconducting material in said vessel, and an electrode extending into saidvessel. I

A potential indicator comprising a sealed glass vessel, liquid insulatorin said vessel, metallic particl in said liquid, and an elec ideextending into said vessel.

A potential indicator comprising a scaled glass tube, a liquid insulatorin said tube, metallic particles suspended in said liquid, and anelectrons extending into said tube.

4. A potential-indieator comprising an insulating-handle, a glass tubemounted in said handle, a liquid insulator in said tube, powderedconducting material in said liquid, and an electrode extending into saidtube.

0 A potentialdndicator comprising insulating-handle, a metallic sleevemounted therein, a glass tube fitting inside said sleeve,

an inner glass tube, an electrode inclosed in i inner tube, aliquid'iusulator in the space between said tubes, and conducting particlin said tune.

iereof have hereunto set my" B. TA YLORQ /i itnessesz V. s J "v--,-enamel-inn is. host, 1- linens Urironn.

